


Half-Monster

by NaughtyButWeiss (RWBYRemnants)



Category: RWBY
Genre: Animal Transformation, F/F, Grinding, Half-Sibling Incest, Incest, Mildly Dubious Consent, Pheromones, Sibling Incest, Sister-Sister Relationship, Sister/Sister Incest
Language: English
Status: Completed
Published: 2016-02-23
Updated: 2017-11-02
Packaged: 2018-05-22 21:16:24
Rating: Explicit
Warnings: Underage
Chapters: 3
Words: 3,572
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/6094240
Author URL: https://archiveofourown.org/users/RWBYRemnants/pseuds/NaughtyButWeiss
Summary: <blockquote class="userstuff">
              <p>For a while now, Yang has been noticing her rage takes longer and longer to fade when she goes into berserker mode. One day, it finally becomes clear that it's more than just on the inside. [nsfw, Enabler/inc3st; complete]</p>
            </blockquote>





	1. Chapter 1

**Author's Note:**

> by: NaughtyButWeisss  
> ship: Enabler (Ruby/Yang)  
> universe: canon divergence, mosnter!Yang
> 
> WARNINGS: Incest, almost-dubcon
> 
> Thinking about doing more with this, but dunno yet. We'll see.

The urges had finally taken over Yang Xiao Long's body. Every time her anger overflowed, she felt them building, but always managed to fight them down. Not tonight. They burned and burned and burned, and she knew something was wrong but didn't care, couldn't stop it. Ever since Blake had been injured by the White Fang, she hadn't been able to keep a lid on it... and now the rage finally had taken over completely. Her eyes flamed and her hair and skin gave off sunlight as she destroyed the heavy bag, as she stomped back to her room. She didn't know what she was going to do, but she knew she had to move, had to keep going.

Ruby Rose seemed surprised when she walked in, startled. Fearful. She wanted to attack her for displaying so much fear - but she fought that down, ignored that. She was saying something about her looking different. "Horns." It sounded ridiculous, she could barely understand her through the curtain of rage. Why would she have horns now when she never did before? Complete nonsense.

Then she scented it on the air - something full, rich, alluring. What she smelled from Blake on occasion. Was she back from the hospital, waiting for her? Immediately, her desire flamed to the surface and her head swivelled to and fro, looking for the source of that intoxicating aroma. No one was in the room but her half-sister.

And then she saw the colour in Ruby's cheeks. _No._

Yang was suddenly even more angry than before. Her little sister wasn't allowed to do that, wasn't allowed to feel those feelings! Especially if someone else was causing them; she wasn't ready for that.

Suddenly, she was pinning Ruby to her bed by her wrists, smelling her hand while she squealed and tried to push the larger girl off. Her voice was a growl when she demanded to know what Ruby had been doing before she came in. That look of shame was coupled with another flare of the scent, and both Yang's primal rage and her desire were redoubled. She could not hide her indiscretion - and Yang could not hide her hunger.

As her mouth hung open, panting, she demanded to know what man made her body feel that way. Ruby didn't answer, but she did reach up to tug at something above Yang's head. She felt it dip forward - there _were_ horns, it seemed. Being grabbed by them made her slam her hips down against Ruby's, and she heard the girl groan... but it wasn't a groan of pain.

Her mind was a fog as she slid down toward Ruby's skirt, jerked it up roughly. Ruby was protesting in the background, saying something, but the blood rushing in her ears blocked it out. The stronger scent was calling to her, and she pressed her face into her cotton panties. The gasp from above was muted, and repeated itself when she began to rub her lips against the damp stretch of cloth, picking up vague hints on her palate of her sister's essence until she could bear it no more. Her hand wandered up, hooked on the waistband-

And then she felt a firm grip pulling her head up and away from what she wanted. Ruby's silvery eyes were full of tears and more were falling.

Finally, Yang's heat-hazed vision cleared. Her senses came back to her, and her eyes returned to normal, and she was left with a sobbing, panting Ruby who was staring at her as if she didn't know her anymore. The memory of what she had just done seemed like a bad dream, so indistinct were the impressions... but the proof was right in front of her. She could still catch Ruby on the air, still taste her on her lips. This was the worst thing she could ever have done.

The words "I'm sorry" weren't enough, but she offered them anyway. As Ruby's hands slipped off her horns, she nodded, but she was still flushed completely red as she quietly cried.

"Can... I be alone... for a little while? I..."

The smell was growing stronger instead of weaker. All Yang did was lay her hand on Ruby's thigh, and she let out a shaky breath. She nodded, but when she leaned in to peck her on the cheek, her lips found her mouth instead. Another whisper of "I'm sorry," but Ruby's lips finding hers cut it off, even as her hands were pushing Yang away. Then Yang gripped Ruby's upper arms - hard, maybe bruising - as she kissed back, to keep them from breaking apart. The fist in her chest made her pull away, fling herself off the bed entirely and onto the floor.

"I'm not a monster," was the first thing out of her mouth. What a lie. Only a monster would do this. Would hurt Ruby this way, would let the heat that normally boiled under the surface take over, and do the one thing that she could never take back. To her _sister._

"You're not a monster," Ruby affirmed - and it felt both like a knife twisting in her gut, and like a warm, soothing salve. Ruby should hate her, had every right... but she didn't. She was just too pure inside to be capable of that. "Yang... I love you, okay?"

The words caused a reaction they never had before: desire. The wrong kind of pleasure.

Yang ran from the room as fast as her legs would carry her, not caring what she hurt, who she bumped into. She just had to get away. Monsters couldn't stay at Beacon.


	2. Chapter 2

**Notes for the Chapter:**

> Surprise! Decided to do something with this after all. I was gonna do it to post on Halloween but couldn't quite get it finished. There's only gonna be 3 chapters, but I always felt it deserved to have an actual ending. Hope you enjoy!

**=Chapter 2**

There was no way for her to know how many days had passed since she fled into the Emerald Forest. Weeks? Months? Her mind had fled her. She wished she could remember what she had eaten when the brief flashes of sentience came back to her. Or where she was, other than the woods; every tree was familiar and yet unfamiliar. She could be anywhere in the world and it wouldn’t matter.

When Ruby found her, she was feasting on the corpse of some woodland animal or another. It smelled like food; that was all that was important. Sustenance. Survival. Ruby was sustenance to her in one way.

“Yang?” she breathed fearfully. “I… wh-what are you eating?”

A snarl ripped from Yang’s throat that actually surprised her own self. But she made herself stop caring about that and turned back to the meal. It had been hard work to hunt down and kill this, and she had to finish it off before another beast came along and challenged her for the-

“It looks good! Can, um, can I have some?”

Something about that didn’t sound right. Her head raised up and she blinked at her sister, trying to remember why. It wasn’t registering. The fear and nausea was evident in the sweet young woman’s pale face; _that_ was it. That was why her words were so out of place.

There was something she used to do when other people talked to her. What was it?

“Well… I wanted to just come see where you’re living now. Comfy out here?”

Talk. She used to talk when someone talked to her. Lips pulled back past teeth, her fangs dripped with blood and saliva… she growled again. It wasn’t talking, or even close to talking; it was a noise that she used to ward off other predators. Ruby was always better at that than she was, even before the change. But now she didn’t want to talk, or do anything else. Just to eat, to drive Ruby away. Before she had to do something about the intruder to her territory.

“S-so Yang,” she went on, hands in the small of her back as she paced forward nervously — _too_ nervously, too afraid, the fear smelled tempting — “Weiss and Blake wanted me to tell you that… that we all miss you. And me, too! Obviously.”

Yang stared at her with her wide red eyes. She only knew they were red from when she drank at the pond. They used to be another colour, too…

A hand approached her hair, and she leapt away, snarling and raising a hand, fingers now sporting claws at the tips. Flashed in Ruby’s direction, making her draw the hand back… except she didn’t. Hesitated, yes, but didn’t withdraw entirely. The hand kept going, slower than before, and Yang was able to suppress her instinct to flee or to attack. She knew Ruby; her scent was familiar, her face was familiar.

“It’s okay,” she whispered as she caressed over Yang’s lank, greasy hair. “I’m here. I’m your sister.”

Somehow, she couldn’t help leaning into the touch. There was a slight smile on Ruby’s face, and it got wider when Yang crawled on top of her, nuzzling into her neck and causing her to giggle. Arms wrapped around her back, and she bristled, readied to flee, but the embrace was warm instead of restrictive. She licked her-

That _did_ cause another reaction. Ruby shivered, let out a soft sigh. Desires flared back into Yang’s body that she had long since abandoned, buried and left dead. On purpose. This was _why_ she was here: to give herself over to her new life as a monster and to forget the one thing that would make her worse than one.

“Yang…”

Her hips began to slam down into Ruby’s, and she let out a sharp squeak followed by a long groan. It was encouraging. However, after a few more rolls of her pelvis, she felt tugging on her horns, and her head was wrenched to one side. She snarled, but when she saw serious silver eyes staring down into her own, she stilled, waiting to see what would happen.

“Yang, come back to me. Please? I… I need you.”

Those words broke over her. She wanted to take them at face value, to tear Ruby’s stupid cloth-leaves- wait, the word for that was _clothes._ Tear her clothes off with her teeth and claws, devour her in one way or another. But that wasn’t what Ruby meant, and she could feel the truth in them, and feel something within her mind stirring.

“I know you’re in there!” she hissed, voice pleading as she hung onto Yang’s horn despite her beginning to struggle against it, to try throwing her off so she could move as she wished. “Everybody at Beacon misses you! Dad’s asking if I’ve seen you, they’re trying to make me send your stuff back to our house… but I don’t want to lose you! I think you’re still in there and you can come back to us, if you j-just… just forgive yourself!”

The last part really did throw her for a loop. Forgive herself? Ah. For the thing which she was trying to forget about entirely. For nearly hurting her sister. The reason for her flight into the forest. She looked away, panting and her vision swimming.

“Hey, your eyes are turning purple again.” When she glanced back up, Ruby was smiling. “Can you say my name? Can you speak?”

It took an effort of will. Her lips opened and she growled. But after a moment, the growl turned into “Ru… by.”


	3. Chapter 3

**=Chapter 3**

Yang was as shocked as Ruby was to hear her speak. However, unlike Yang, Ruby was ecstatic. “That’s good!” she cried out, throwing her arms around Yang’s neck. She bucked and tried to throw her off, but she held fast, giggling and kissing all over her face. “Yang, I knew you could do it!”

Her animal nature tried to reassert itself. Hind legs braced, launched them both into the bushes and pinned Ruby hard against the leaves, prompting a grunt from her as she was pinned. Her fangs raked along her willowy neck, but Ruby didn’t scream or try to push her away; she only held perfectly still. Somehow, that made Yang kiss her neck instead of trying to bite it, instead of trying to attack. Another sigh of gratitude.

“So… I thought about this part,” Ruby whispered into her hair. “And… if th-this is what you need to come back… then we…” It took her another minute of Yang lapping at her neck, down to her collarbone, before she could finish her thought. “You can have me. I promise, Yang, if you can be my sister again, and mess with Weiss, and make puns, a-and tease me and Blake, and… you can do whatever you want with me!”

Tongue lolling out, she drew back and fixed Ruby with hungry eyes. That sounded good to her. She knew deep down that something wasn’t right about this, that she shouldn’t do anything more, but she only wanted to be with Ruby more than anything else in that moment. The instinct was overwhelming.

Teeth raked down and began to shred Ruby’s bodice, her claws doing the same. Her sister shivered and did let out a shriek at that, and her hands came up to fist in Yang’s hair as a way of bracing herself. That only spurred her on. Again, she found herself facing Ruby’s underwear, though it was stretched over her upper body instead of lower body this time. Her tongue lolled out and slid from navel to the center clasp, fangs slid back and forth over the fabric…

“Good,” Ruby whispered fearfully, shaking all over. “It’s… it’s what you need…”

Her mind sharpened just enough to remember why this was _not_ what she wanted. Only for a moment, but she remembered, and she tried to throw herself off to run away.

“NOPE!” Ruby shouted, grabbing onto her horns. She dragged the smaller girl several yards before the pain on her neck forced her to slow down and collapse to the ground. “Yang, y-you can have me, or you don’t have to, but… but I can’t let you go again!”

Her throat worked and she finally managed to growl, “Nnnno! Ruby… go!”

“Please, don’t do this!”

“I’m… too…” The word wouldn’t come to her. She didn’t care about words anymore. Maybe she could remember every single one Ruby was saying, what they meant, understood them. But she didn’t have any interest in saying them herself.

“You’re my sister and I love you!”

Teeth gnashing, she ground out, “I’m… a monster!”

“I don’t care! Maybe you are, maybe you’re not, it’s- you’re my sister and th-that’s that!”

Tears were leaking down her cheeks now. She tried to run, but the hands held fast, and her throat erupted into a howl that made Ruby duck her head. Yet her hands remained clamped around her horns, dragging her down on top of her soft, pink body and the shreds of red-and-black clothing that still hung gaping open, distressed by her own actions.

“Ruby… I love…” The encouragement to speak wasn’t helping, was making the words come faster despite how badly she _wished_ they wouldn’t. “Want you… smell you, taste… it’s bad, monster, hunger is wrong…”

Again, Ruby forced her head back and stared straight into her eyes. Her voice was deadly serious. “Then take me. Whatever you want. Just don’t leave.”

“No… nnnno…” Why was it so tempting? Because she could scent Ruby’s arousal on the air. Because her body was strong, but soft, vulnerable. Her teeth raked down Ruby’s neck and chest once she was released, but she also started kissing the skin here and there again. “Ruby…”

“Come back with me. We… could help you, I think…”

“Why? Why do you want… me to…”

When Yang sank her teeth into Ruby’s thigh, she called her name, loud and piercing. The scent only grew stronger. How could she hold back after that? Her mouth closed around the softness through the underwear, and even while Ruby’s voice hitched above her, she felt her own hunger growing stronger. She _needed_ her sister then and there. Need throbbed between her own thighs that she wanted to sate, but it was more important she devour first.

When she yanked the cloth aside to taste her directly, Ruby did cry out again. “Yang, no!” But when Yang froze, a hand fell to her hair and stroked. “I m-mean… I… I’m scared, but… if you want me…”

“Want you.”

“Please take me, then.”

She was sweet, and salty, and thrumming with a very mild taste that drove her even more wild than she already was. Her work was so voracious but she found herself able to resist biting down; she wanted her sister to love what she was doing, too. Which was as shocking as wanting to do it herself. Very little time had passed before she felt Ruby convulsing, squeaking into a closed fist to muffle her cries of ecstasy. She hadn’t expected it to happen that fast. She kept up her motions until Ruby had stopped completely, then raised her head to stare at her, panting.

“Good? For you?”

“Good,” Ruby agreed with a breathy little laugh. Her red-and-black hair was plastered to her forehead, and her eyes half-closed. “Did you, um… was I tasty? I don’t really know what I’m asking…”

“Very good. I need…”

Surprising both of them, Yang crawled onto her and began to grind her hips against Ruby’s soft thigh. The girl yelped, then giggled a little. “Yang, you’re worse than Zwei!” But Yang was too single-minded in her pursuit of pleasure to take that in. “Oooh… I can feel you, so warm and wet…”

It didn’t take her long, either. Never would she have predicted she’d rut against her own sister’s leg to bring herself to climax, but Ruby stayed beneath her, sharing kisses and stroking along her nude back. Within minutes, she was howling into the branches above.

“Oh my God, Yang,” she whispered as she fell limp atop her. “We did it. I think? Yeah, that really feels like…” After gulping, she wrapped her arms more tightly around her. “And it’s okay! I mean, it’s weird, but I… I’m happy. I got to spend time with you.”

“I’m happy, too,” she breathed, snuggling down against her. “Even if you did compare me to Zwei.”

They both drew back and gaped at each other. After a few seconds, Ruby whispered, “You sound like _you_ again!”

“What? I mean, uhh… I do.” She blinked a few times, then shook her head violently. “It’s… I still feel… angry, and strange… hard to think sometimes. But like, I think I’m back. Kind of.”

“Where did you go to come back from?” Ruby asked, very much needing to know.

“I was… so angry. About Blake.” She raised her hackles to think about it again, but Ruby kissed her cheek and she was able to let the feeling fade. “And… and then I came in, and you had been getting yourself off… and it was like, my anger focused on that… which was stupid. A-and when we started turning each other on, and I almost hurt you, I just… couldn’t…”

This time, Yang did start to change again, more fully. She backed away from Ruby, shaking out her head, the voice of her sister fading to just noise. But firm hands grasping her horns brought her around.

“…not that bad,” Ruby was saying when she could understand her again. “I love you.”

“Love? Me?” Then she shivered, trying to find that place she had reclaimed again. “I m-mean… yeah, I love you, too. Sorry. I’m so sorry, Ruby!”

As she sobbed into her sister’s shoulder, Ruby started whispering, “We’ll talk to Ozpin. He can help. But even if he can’t… I’m not going anywhere. I love you so much, sis! And… and doing it with you felt great, so please don’t think I was just, like… ‘putting up with it’ or whatever!”

“Really? You wouldn’t rather do it with someone who’s not your… y-your own-”

“Nope!” she headed her off, which helped to keep her soul in place. “But I do think maybe we should, like… _try_ to take some time off doing that. See if it’s what we really want. And if we do, well, I think we’ll be okay. Because that was a lot of fun.”

At last, Yang leaned up and waggled her eyebrows a little more like her old self would have. “You bet it was. Didn’t figure you for a screamer.” At Ruby’s amazingly pretty blush, she felt a little warmth creeping into her own face. “Wow… this is really messed up.”

“Yeah. But… I got my sister back, and finally got laid! Everything else is just dumb details.”

“Guess so.” As they finally stood, Yang put her hands on her bare hips. “Gonna be pretty embarrassing to walk back into Beacon naked, though.”

“I could loan you some of my clothes, but you kinda fucked them up.” When Yang sighed, she giggled. “But it’s okay. You’re not a monster anymore, and that’s way more important than a pair of panties.”

“I’m _half-_ monster,” Yang corrected, tapping her horns. “Seriously, I’d love to hear Ozpin or Goodwitch explain where these came from…”

“Tomorrow,” Ruby said sweetly as she put her hand into her sister’s and they began to walk through the Emerald Forest and back toward the school. “Tonight, let’s just get back home so you can take a shower, stinky half-monster.”

Yang’s grin was still a little vicious, but mostly just lewd. “As long as you shower with me.”

“ _YANG!”_

THE END


End file.
